Engine cooling system with radiator by-pass



Fab; 1959 R. T. DOUGHTY 2,871,836

ENGINE COOLING SYSTEM WITH RADIATOR BY-PASS Filed Jan. 18, 1956 2 Sheets-Sheet 1 INVENTOR v r I I fioiziI-Qagi AT TORNEY v R. 'r. DOUGHTY ENGINE COOLING SYSTEM WITH RADIATOR BY-PASS Filed Jan. 18, 1 956 Feb 3, 1959 2 Sheets-Sheet 2 Inventor w! aod yg United States Patent "i ce ENGINE COOLING SYSTEM WITH RADIATOR BY-PASS Robert T. Doughty, Detroit, Mich assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application January 18, 1956, Serial No. 559,882

5 Claims. (Cl. 123-41.1)

This invention relates to engine cooling systems and more particularly to such systems each employing a radiator in combination with a thermostatic valve for lay-passing the radiator when the systems are at below normal operating temperatures. A satisfactory system of this type is disclosed in the United States Patent No. 2,244,932, issued June 10, 1941, in the name of Orlin L. Anders-on and entitled Thermostatically Controlled Engine Cooling System. Other systems of this general type are also known and have obtained various degrees of success but each is subject to one or more of the following disadvantages: complexity of structure; costly to manufacture; lack of desired reliability and ruggedness; and unduly restrictive to radiator by-pass coolant flow.

An object of the present invention is to provide an improved engine cooling system of simple construction giving a maximum flow of coolant for circulation through the cooling jacket arrangement of an engine when the function of a radiator is not required.

Another object is to provide a system in which a thermostatic valve is so associated as to provide coolant flow through an engine coolant jacket arrangement when the engine or coolant is at below normal operating temperature thereby reducing localized engine heating and possible fuel detonation, as well as to reduce the engine block warm-up period.

To these ends, a feature 'of the invention pertains to a thermostatic valve so associated .with ports in a cooling system that one of those ports is restricted or cleared by an imperforate cylindrical portion of the valve dependent upon the temperature of the coolant. Another feature is an imperforate cylindrical valve portion of substantially less diameter than that of an associated port whereby the restriction of the port by the valve portion cannot be complete and thereby avoiding undue chilling of the valve portion.

These and other important features of the invention will now be described in detail in the specification and then pointed out more particularly in the appended claims.

In the drawings:

Fig. 1 is a fragmentary side elevation, with parts in section, of an internal combustion engine of a type conventionally used in automobiles and equipped with a cooling system embodying the present invention and looking substantially in the direction of the arrows 11 in Fig. 2; and i Fig. 2 is an elevational view drawn to an enlarged scale of a portion of the cooling system as supported on an engine and as shown in Fig. 1, parts of the system being broken away better to illustrate the construction.

In utilizing the present invention, a thermostatic valve 10 is employed which is of a type utilizing an imperforate cylindrical portion 12. Such a valve is disclosed in the United States application for Letters Patent Serial No. 510,210, filed May 23, 1955, in the names of Hugh I. Clifford and Adolf Schwarz and entitled Thermo- Responsive Control Valve Assembly. Details of this valve may be modified or other forms of such valves may Patented Feb. 3, 1959 be employed without departing from the present invention and, accordingly, a detailed description of the specific valve construction is not included herein. It may be stated, however, that the valve shown in the drawings includes a frame 14 supported on a fiange member 16 and the cylindrical valve portion 12 is of pellet type construction to function as a heat actuated motor--i. e.- encloses athermo-sensitive material which, upon expansion, causes the portion 12 to lower and thereby carry with it a disc valve 18 into an open position away from an annular seat on the member 16. The frame 14 has two oppositely disposed arcuate openings 15 and 17. The flange member 16 is provided with main ports 19 and 20 (Fig. 1) and with one or more small ports 21 (Fig. 2) near its periphery. When the disc valve 18 is caused to open, it must do so against the compressive force of a coil spring 22 located within the frame 14. The application of heat causes the portion 12 to withdraw from a stationary threaded pin 23 as disclosed in the patent application abovereferred to.

In Fig. 1, an internal combustion engine 24 is depicted with a cooling system casting 26 aifixed thereto by means of bolts 28. A conventional radiator 30 is mounted forwardly of the engine and is provided with inlet and outlet fittings 32 and 34, respectively. A conventional cooling fan 36 is mounted between the radiator and the 'casting 26 on a shaft 40 which also serves as a power shaft for a water pump impeller or rotor 42. The pump impeller and fan are rotated by means of conventional pulleys 44 and 46 connected by a belt 48 and actuated by the engine. The fan and pump shaft 40 are journaled in a hub 50 formed on the casting 26 and sealing means 52 are provided in the casting and around the shaft 40 to prevent water leakage.

The top portion of the casting 26 is provided with a substantially horizontal passage 60 having endports 62 and 64 communicating wtih the cooling jacket arrangement employed on the engine. An intermediate portion at the top of the casting 26 is flattened 01f to present a supporting surface 66 for a conduit fitting 68 fixed thereto as by means of screws 70. The casting 26 bears a top opening 72 in which the thermostatic valve 10 is supported. A recess '74 is provided in the casting so that the flanged member 16 is snugly held therein when confined by the fitting 68. A flexible hose 76 connects the fittings 68 and 32.

The'casting 26 also includes a vertical duct 80 which terminates with a horizontal wall 82 spaced from the valve frame 14 and having a port 84 coaxial with the valve port controlled by the valve disc 18. It will be noted that the port 84 is appreciably or substantially larger than the cylindrical valve portion 12 with which the port or duct is associated or aligned. The relationship of the portion 12 with the port 84 forms an important and novel aspect of the present invention.

Also integral with the casting 26 is a coolant pump casing 86 having tangential connections 88' and 90 to which hose may be connected as at 92 and 94, respectively, for directing and receiving water for the vehicle heaters. The pump casing 86 is provided with outlet conduits 96 and 98 which lead to ports 100 and 102, respectively. Theseports are adapted to lead to the engine block arrangement at points spaced from the ports the invention is to be used on a single block engine such as a conventional four or six cylinder engine.

Also integral with the pump casing 86 is an inlet couduit 106 which is connected by means of a hose 108 to the radiator outlet fitting 34.

It will be appreciated that the thermostatic valve may be removed or replaced simply by disconnecting the fitting 68 from the casting 26.

In operating the cooling system and assuming that the associated engine 24 is cold, the temperature sensitive material in the cylindrical valve portion 12 will be contracted permitting the spring 22 to hold the valve disc 18 on its seat and causing the cylindrical valve portion 12 to clear the port 84. These positions are illustrated by solid lines in Fig. 2 in which figure it will be noted that the arrows showing the flow and drawn with solid lines illustrate that the coolant flowing from the engine by way of ports 62 and 64 passes downwardly through the port 84 and the duct 80 again to be discharged by the pump impeller 42 back to the engine by Way of ports 100 and 102. The port 84 or the duct 80 is, accordingly, free of obstruction or restriction and maximum flow of coolant is assured for the engine cooling jacket so that no localized hot spots may develop therein. Simultaneously with this action a small quantity of the coolant may flow through the openings 21 to the radiator 30 so that the radiator and associated inlet and outlet fittings may gradually increases in temperature without detracting appreciably from the rate of warm-up of the engine.

After the engine 24 or coolant has become adequately heated or has acquired a normal operating temperature, the valve 12 will be affected thereby and expansion of the therrno-sensitive material Within the cylinder portion 12 will cause the latter to assume the position indicated by the dash lines in Fig. 2. As a result, the port 84 will be partially restricted by the cylindrical portion 12 and the valve 18 will be opened accompanied by forced compression of the spring 22. Under these circumstances the by-pass connection to the pump by way of the duct 80 is curtailed in its operation or rendered less effective and the primary flow of coolant is then upwardly directed through the frame openings 15, 17, 19, of the valve 10, fitting 68 and the hOSe 76 to the top of the radiator 30. After being cooled in the radiator the coolant again enters the pump by way of the hose 1138 and the conduit 1% for conventional or normal circulation through the engine cooling jacket arrangement by way of the ports 100 and 102.

The cylindrical valve member 12 has been described as substantially smaller in diameter than the port 84. As a consequence, a substantial clearance exists when the port 34 is restricted by the portion 12. This clearance is sufiicient to prevent the portion 12 from becoming chilled when the engine is Warm or heated to a normal operating temperature. It will be appreciated that the valve 19 should maintain an open passage into the fitting 68 when the engine is at operating temperature and with this end in mind, the therrno-sensitive material in the valve 10 must not be subjected to the possible cooling effect of a closed pocket of coolant within the duct 80. Regardless of the engine coolant temperature at any given time it is obvious that the portion 12 is so located as to function rost effi-ciently in that a substantial portion of it is always in intimate contact with the coolant immediately after the latters emergence from the engine block.

I claim:

1. An engine cooling system comprising conduit means arranged to recirculate a-cooling medium through an engine cooling jacket arrangement by way of a radiator, said means including a duct by-passing said radiator, a port in said means controlling flow to said radiator, a thermostatic valve controlling said port and including an imperforate cylinder portion arranged to enter and emerge from said duct dependent upon the temperature of said medium, and said portion enclosing thermo-sensitive material causing said portion to function as a heat actuated motor.

2. An engine cooling system comprising a radiator, a pump and conduit means for conducting a cooling medium to and from an engine cooling jacket arrangement by way of said radiator, said conduit means including a duct leading to a pump and by-passing said radiator, a port in said conduit means controlling flow to said radiator, the said duct and port being substantially coaxial, a thermostatic valve having a valve disc arranged to control said port and including an imperforate cylinder portion arranged to clear said duct when said valvle is cooled by said medium and to partially restrict said duct when said valve is heated by said medium, and said cylinder portion being a heat actuated motor which is bodily movable with said valve disc.

3. An engine cooling system comprising a radiator, a pump and conduit means for conducting a cooling medium to and from an engine cooling jacket arrangement by way of said radiator, said conduit means including a duct leading to a pump and by-passing said radiator, a first port controlling fluid flow through said duct, a second port in said conduit means controlling flow to said radiator, the said ports being Substantially coaxial, a thermostatic valve having a valve disc arranged to control said second port and including an imperforate cylinder portion with a substantially smaller diameter than that of said first port, said cylinder portion being arranged to clear said duct when said valve is cooled by said medium and partially to restrict said first port when said valve is heated by said medium, and said cylinder portion being a heat actuated motor enclosing thermosensitive material located on one side of said valve disc.

4. An engine cooling system comprising a radiator and conduit means for circulating a cooling medium through an engine cooling jacket arrangement, said means including a duct leading to a pump and by-passing said radiator, a main port in said conduit means leading to said radiator, a valve disc arranged to control said main port, an imperforate cylinder portion fixed bodily to move with said valve disc and arranged to enter and emerge from said duct dependent upon the temperature of said medium, a pin fixed in said conduit means, and said cylinder portion retaining thermo-sensitive material around one end of said pin.

5. A system such as set forth in claim 4 in which the structure defines a restricted flow path for said cooling medium around each end of said cylinder portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,791,572 Ornberg Feb. 10, 1931 1,986,235 Mayo Jan. 1, 1935 2,244,932 Anderson June 10, 1941 wu' ri in 

